Adolescence is a critical period for neurodevelopment. In the present study, we investigated the effects of pen-adolescent social isolation on latent inhibition (LI) and dopamine 02 receptor expression in the medial prefrontal cortex (mPFC) and nucleus accumbens (NAc) of young adult rats. Male Sprague-Dawley rats were randomly divided into adolescent isolation (ISO; isolated housing, 21-34 days of age) and social housing (SOC) groups. LI was tested at postnatal day 56. After behavioral testing, the number of dopamine D2 receptor-expressing cells was determined using immunohistochemistry. Adolescent social isolation impaired LI and increased the number of cells expressing the D2 receptor in the mPFC and NAc. The results suggest that adolescent social isolation produces profound effects on cognitive and dopaminergic function in adult rats, and could be used as an animal model of various neurodevelopmental disorders. (C) 2012 Elsevier B.V. All rights reserved.

This work was supported by the National Natural of Science Foundation of China (grant No. 31070910, 30500158), National Basic Research Program of China (973 Program, 2007CB512306), the Chinese Academy of Sciences (KSCX2-YW-R-131), American Psychological Association, and grants to young scientists from the Institute of Psychology, Chinese Academy of Science (O9KF013001).